This invention is a medical device and relates generally to the field of punch devices used in performing anastomosis (the joining of a hollow or tubular organ to another hollow or tubular organ), and in particular such devices used in the surgical joining of a vein graft to the aortic wall, where the punch device is used to create the hole in the aortic wall.
In coronary bypass surgery, a blocked segment of the coronary artery is bypassed by attaching a vein graft to the aorta above the blocked point and to the artery downstream of the blocked point, such that blood flow is routed around the blockage through the vein graft. In a common technique used to attach the graft, a hole is created in the aortic wall by first creating a small slit using a scalpel. The cutting disk of a punch device is then inserted through the slit. The cutting disk is mounted onto a thin shaft, which is coaxially received by a tubular sleeve member, the end of which is provided with an annular cutting edge or rim. With the aortic wall between the disk and the sleeve, either the disk is retracted into the sleeve or the sleeve is advanced beyond the disk. This operation cuts a circular opening in the aortic wall, and the plug cut from the wall is entrapped within the, sleeve and disk. The punch device is then removed and the surgeon proceeds with the anastomotic procedure.
It is necessary to temporarily occlude the opening in the aortic wall in some manner after removal of the plug to prevent excessive loss of blood during the anastomotic procedure. The most commonly employed method is to apply a C-shaped surgical clamp to the side of the aortic wall at the proposed site of the anastomosis prior to cutting the aorta and introducing the punch. The clamp compresses only a portion of the aorta, allowing continued blood flow past the clamped area. This technique can be problematic in that application of the clamp may cause damage to the aorta or release plaque fragments or atheromatous debris into the blood stream when the clamp is released.
One alternative technique for blocking blood flow through the hole created in the aortic wall by a combination punch device is shown in U.S. Pat. No. 5,944,730 of Nobles et al. The Nobles et al. device, as described in the second embodiment of the disclosure, is a grossly elongated instrument having an occluding inverting member mounted onto the distal end of a long, slender flexible tube, an inverter handle assembly, and an intermediately disposed punch assembly. The punch assembly is joined to the inverter handle assembly in a disconnectable fashion, such that the punch assembly is detached from the inverter handle assembly and slid distally along the flexible tube to remove the plug from the aortic wall, after which it is translated proximally and rejoined to the inverter handle assembly. The inverter handle assembly is then manipulated to cause the inverting member to fold onto itself into a conical configuration and the entire device is pulled in the proximal direction to seal the aortic wall. Each end of the inverting member must be attached to a different elongated tubular member which are slidably movable in the axial direction relative to each other. The provision of separable punch and inverter handle assemblies, the elongated flexible tube on which is mounted the occluding member, and the overly complicated design of the occluding member results in an awkward instrument of excessive length which is difficult to operate in an efficient and straightforward manner. Additionally, there is no structure to block blood flow through the hole in the aortic wall during the time period while the punch assembly is being withdrawn and rejoined to the inverter handle assembly prior to expansion of the inverting member and retraction of the apparatus.
It is an object of this invention to provide an anastomosis punch device for creating a hole in the aortic wall, and method of use for same, which has an occluding structure to prevent blood from exiting the hole created in the aortic wall during attachment of the vein graft, where the device comprises an elastic dam membrane having circumferentially spaced longitudinal ribs, where the ribs may be spread to open the membrane into a conical configuration in an umbrella-like manner to surround the hole, then collapsed for withdrawal after the vein has been partially secured, where the dam is affixed to the shaft of the punch assembly distal to the annular cutting disk and the cutting sleeve, where the cutting sleeve blocks blood flow through the hole created in the aortic hole prior to expansion of the elastic dam membrane, such that the punch device is a compact instrument which is easily manipulated by the surgeon.
The invention comprises an anastomosis punch device, and method of using same, for creating a circular hole in the aortic wall, where the device also segregates the hole from the blood flow path such that no blood is lost through the hole during attachment of the vein graft. The invention is a compact hand-held punch comprising an elongated housing to be gripped by the surgeon, the housing retaining in a coaxially aligned manner a cutting disk, a cutting sleeve having a distal cutting rim which cuts a circular plug in cooperation with the cutting disk, an expandable, umbrella-like, flexible dam formed of an elastic tubular material and adjoined to the shaft of the punch assembly distally to the cutting disk and cutting sleeve in a manner which allows it to be deployed radially outward with the enlarged open rim facing the proximal direction, and a deployment ram movable axially relative to the dam to spread open the dam. The surgeon inserts the punch head, the elastic dam and cutting disk through the aortic wall, then advances the cutting sleeve against and over the cutting disk to remove a circular plug of aortic wall, with the plug being retained within a chamber defined by the cutting sleeve and the cutting disk and the cutting sleeve locked in the advanced position. The ram is then advanced relative to the dam, causing the proximal end of the dam to spread outwardly to form a cone shape, and the ram is locked in position. The rim of the expanded dam is then drawn against the interior wall of the aorta, thus forming a conical dam about the hole. The vein graft is then attached to the aortic wall at the hole using known suturing techniques while the device remains in place. Once the vein is sufficiently attached to the aortic wall in loose manner, the ram is retracted relative to the dam, allowing the dam to collapse into the passive configuration with minimal diameter because of the elastic nature of the membrane. The entire device is then withdrawn between the sutures and completely out of the aorta, with the sutures then quickly tightened to connect the vein graft to the aorta.